TWI374640B - A method of transmitting feedback information in a multi-input, multi-output (mimo) system - Google Patents

Description

1374640 » LUXURY IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to a method of transmitting feedback information, and more particularly to a method of transmitting feedback information in a multiple input/output (ΜΙΜΟ) system. [Prior Art]

A multiple input/output (ΜΙΜΟ) system searches for improved frequency efficiency and network link capability by using a plurality of antennas in a base station (BS) and in a mobile station (MS). In this connection, the ΜIΜ system has gained a lot of attention in a practical technology for transmitting high-speed data in a mobile wireless communication system.

In a closed loop system having a plurality of antennas, the M S receives data transmitted from the B S and estimates channel information for each channel. The MS then uses the evaluated channel information to obtain a weight value, which is then transmitted to the BS as feedback information. After receiving the feedback information, the BS applies the weight value to the input data to be more efficient and more efficient in transmitting the input data to the MS. In an Orthogonal Frequency Division Multiplex/Orthogonal Frequency Division Multiple Access (OFDM/OFDMA) system, the B S receives various types of feedback information from the M S for application to the downlink signal. In this system, various modes can be applied to the transmission in accordance with the data transmission scheme used by the multiple antennas of the transmission side. These modes include a time-space divergence transmission (STTD), a spatial multiplexing

5 1374640 _ « (SM), with a closed loop rate SM. In addition, in the closed loop system, there are five types of feedback information that can be transmitted from the MS to the BS. The first type is an antenna group index. The antenna group index is applied when the closed loop STTD scheme is used. A pair of antennas that have reached STTD can be changed based on the channel state, and the optimal set of antennas can be provided to the BS by the MS.

The second type is an antenna selection index. When using a closed loop STTD scheme or an SM scheme, the antenna selection index is applied. More specifically, a specific number of antennas having the best channel state can be selected from a plurality of antennas, and the indices of the selected antennas are transmitted to the BS °

The third type is a precoded thin index. The pre-encoded thin index is applied when a closed loop S Μ scheme is used. More specifically, the precoding matrix codebook is a multiple of the transmission signal at the BS transmission antenna group, which can be reserved by both the BS and the MS, and the MS selects and provides the i th The best precoding matrix for the channel state is given to the BS. The fourth type is a direct pre-encoded matrix value. This direct pre-encoded matrix value is applied when a closed loop SM scheme is used. More specifically, the MS directly provides the pre-encoded matrix value. The precoding matrix is a multiple of the transmission signal of the group of transmission antennas in the BS.

The fourth type is the number of streams. When an STTD scheme or an SM scheme is used, the number of streams is applied. More specifically, the MS provides the number of transmission signals that can be used in either scheme to achieve the best transmission capability for the BS 6 1374640. Here, the number of transmission signals is the same as the number of transmission symbols that are simultaneously transmitted. In addition to the five types of feedback information, the feedback information may include the MS selected UI mode and an alignment scheme associated with the selected mode. This detail will be provided below.

In the OFDM/OFDMA wireless communication system, the MS determines the arrangement and transmits the determined arrangement to the BS in the form of feedback information. Here, the decision of the arrangement means that the MS decides the scheme by arranging and arranging data for data transmission in a frequency wide frequency. That is, the MS may select one of the all-subcarrier (FUSC), one of the subcarriers (PUSC), and any one of the adjacent subcarrier arrangements.

In the closed loop system, the feedback information for transmitting the UI mode and the arrangement scheme selected by the M S or the weight value applied to the downlink transmission can be completed using the following procedure. First, the BS transmits the MS information, the MS information includes a feedback type for transmitting feedback information to the BS, and a feedback time period for the BS according to the MS English transmission feedback information. This information can be transmitted using any one of the information elements (IE) to provide a channel quality information channel (CQICH), a fast feedback configuration subheader along with the data transmission, and a feedback wheel used by the BS to configure the upload resource. Inquiry (poIling) IE.

After receiving the feedback type and the information of the feedback period, the MS may periodically transmit the feedback information using a fast feedback channel on a configuration frame, or use a feedback header on the configuration upload frame to cycle. The feedback information is transmitted (or aperiodically). If there is a data transmitted to the B S 7 1374640 * «, the MS uses the header to transmit the data. Regarding the above description, the following problems exist. First, a procedure for transmitting (returning) a pattern and an arrangement selected by the MS is completely different from a procedure for transmitting (returning) a determined weight value. Second, although there are currently three methods for transmitting weight values that can be applied to downstream transmissions, there is no way to know what method to apply. Finally, it is not possible to reveal a method related to transmitting a direct pre-encoded matrix value.

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a method of transmitting feedback information in a multiple input and output (MIMO) system that substantially obviates one or more of the limitations and disadvantages of the related art. problem. It is an object of the present invention to provide a method of transmitting feedback information in a multiple input/output (ΜΙΜΟ) system.

Additional advantages, objects, and details of the invention will be set forth in the description which follows in the description which know. The objectives and other advantages of the invention will be realized and attained by the <RTIgt; To achieve these objects and advantages, and in accordance with the purpose of the present invention (as embodied and summarized herein), a method of transmitting feedback information in a multiple input/output (MIMO) system includes a mobile station (MS), which Mobile station 8 1374640 • i can decide to transmit feedback information and feedback type to a base station (BS) without request from the BS, wherein the feedback type is a transmission antenna type, and the transmission wheel should use one The ΜΙΜΟ mode feedback extends the sub-header feedback information 'where the ΜΙΜΟ mode feedback extended sub-header occurs between a media access channel (MAC) header and a payload (payi 〇 ad).

In another aspect of the present invention, the MS generates a protocol data unit (PDU) including a media access channel (MAC) header, an extended sub-header group, and a payload, wherein the MAC The header includes information whether or not an extended sub-header group appears after the MAC header, and wherein the extended sub-header group includes a ΜΙΜΟ mode feedback extended sub-header. In addition, the MS transmits the PDU, the PDU includes the MAC header and the ΜΙΜΟ mode feedback extended subheader, wherein the ΜΙΜΟ mode feedback extended subheader includes a change for an antenna transmission type. request. It is to be understood that both the foregoing general description and the claims

[Embodiment] The present specification will refer to preferred embodiments of the present invention, and the examples illustrated in the drawings. Wherever the same reference signs are used throughout the drawings, reference is made to the same or similar parts. In the traditional field A does not have a way to inform the existence of a quick upload feedback subheader. Tables 1 and 2 show examples of data formats for a mode selection feedback subheader:

9

1374640 • I

[Table 1] Name Length Description (bit) Feedback type 4 Indicates the type of feedback (see Table 2). Feedback content 4 Content of this feedback [Table 2] Feedback type Description ObOOOO ΜΙΜΟ mode and arrangement. If set to this type, the feedback content is as described in Table 3. ObOOO1-Ob 1111 Reserved

After selecting one of the modes used for transmission and a permutation scheme, the mode selection feedback subheader is used by the M S. This mode selects the feedback subheader not used by itself. That is, as shown in Figures 1 and 2, an extended sub-header (ESF) informs the mode to select the presence and content of the sub-header. More specifically, Fig. 1 shows an example of a data structure of a medium access channel (MAC) protocol data unit (PDU) in an OFDMA wideband wireless access network system. Fig. 2 shows a detailed description of the ESF of Fig. 1. 10 1374640 As shown in Figure 1, by including a pointing field to indicate the presence or absence of an ESF, more and/or different types of sub-headers may be included between the header and the sub-header. In order to distinguish the difference, because the ESF block contains 2 bytes, the 11-bit bitmap can be used to represent the existence of 11 sub-headers, while the remaining 5 bits are available. To indicate the size of the subheader. Table 3 shows the arrangement of a mode and mapping to a 4-bit payload. [Table 3] Value description ObOOOO STTD and PUSC/FUSC by g 歹ij ObOOO 1 STTD and adjacent subcarrier arrangement ObOO 1 0 SM and PUSC/FUSC arrangement ObOO 1 1 SM and adjacent subcarrier arrangement ObO 1 00 Closed loop SM Arrange with PUSC/FUSC 0b0 1 0 1 Closed loop S Μ Arranged with adjacent subcarriers ObO 1 10 Closed loop SM plus Beamforming and adjacent subcarrier arrangement 0bl000~0bl111 Reserved

Table 4 is an example of a data type of a fast upload feedback sub-header, which is in a closed loop system after the MS determines the weight value for the downlink transmission quality enhancement, like a feedback 11 1374640 * * Transfer to the BS. [Table 4] Name Length (bits) Description Feedback type 2 Indicates the type of this feedback. The same mapping is applied to the feedback type field in Table 5. "Feedback Content 6 This same mapping is applied to Table 5.

Table 5 describes an example of a feedback content. In Table 5, the index value, which indicates the antenna group, the antenna selection, and the pre-encoded codebook, can be used for any three values from OblOlllO~ObllOllO.

[Table 5] Value description OblOlOOO STTD and PUSC/FUSC·^ 歹|J Ob 10 1 00 1 STTD and adjacent subcarrier row 歹 Ob1 1 1 1 1 1 1 SM 1 and SMSC/FUSC 歹 歹 Ob1 1 1 1 1 1 1 1 SM and adjacent subcarrier arrangement Ob 1 0 1 100 Hybrid and PUSC/FUSC 歹 ij 0b 1 01 1 0 1 H ybrid adjacent subcarrier arrangement 0b 1 0 1 110~Ob 110 According to Table 296e, 296for 296g literal translation, Depending on the 12 1374640 * ♦ 110 antenna group used, antenna selection or a reduced precoding matrix codebook. Ob 1101 1 1 together with the first stream for closed loop precoding Obi 1 1000 together with the second stream for closed loop precoding Ob 1 1 1 00 1 together with the third stream for closed loop precoding Ob 1 1 1 010 together with the 4th stream for closed loop precoding Ob 11101~0b 1 1 1 1 1 1 Reserved

In order to improve the downlink channel capability, the BS transmits a feedback type and a feedback period to the M S to receive the channel estimate and a method of transmitting the most appropriate mode and weight value in the closed loop system. This may also be used to pass the rim mode change request or to use a method of transmitting a pre-coded weight/antenna weight value like feedback information to the BS without requiring a request from the BS.

If the BS requests or solicits a particular feedback type, the MS transmits an indicator to indicate the particular feedback type and, as the feedback, responds to the content to the BS. Even if the MS does not receive any request or request from the BS, the MS may voluntarily select and transmit the desired/preferred chirp mode, or use a pre-coding weight/antenna weight value to transmit to the BS. method. For example, if a specific feedback type is transmitted to the BS, if the MS has data transmitted to the BS, preferably, the MS is included by including the sub-header of the MAC PDU (for example, the ΜΙΜΟ mode feedback sub-header) An indicator for indicating the 13 1374640 feedback type and the feedback content to transmit feedback information. As described above, Fig. 1 shows an example of a structure of a MAC PDU data according to an embodiment of the present invention. In Fig. 1, in accordance with the particular embodiment of the present invention, the presence of the ΜΙΜΟ mode feedback sub-header is represented by the ESF, which occupies a portion of the header. Moreover, the sub-header type that can be used by the ESF can be determined, and at the same time, the size of the ESF is determined according to the feature value of the sub-header (for example, the number of sub-headers and the type of sub-headers) .

Figure 3 is a diagram showing an example of a process between a mobile station (MS) and a base station (BS) in accordance with an embodiment of the present invention. In Figure 3, the BS transmits the MAC PDU, which includes the ESF and the secondary header to indicate the type of feedback. Based on the received object, the MS determines the sub-header position that can be included between the header and the payload. The MS determines the necessary information for the type of feedback. From then on, the MS can transmit the header to the BS without the payload to notify the BS that has determined the type of feedback.

Table 6 shows an example of a bitmap architecture that informs the ESF of the presence of the sub-header in the ESF. [Table 6] ESF Bit Name Length (bytes) #0 (LSB) UL ΜΙΜΟ mode feedback subheader 1 # 1 Reserved Table 7 describes an example of ΜΙΜΟ mode feedback subheader content. In the 14th 1374640 * f 7 diagram, the "reward type" has a length of 2 bits and functions as an indicator for the content searched by the MS to make a request. Further, "reward content j has a length of 6 bits and can have the ability to discriminate the method applied in OblOllO~ObllOllO of Table 5. [Table 7]

Name length (bits) Description Feedback 2 0 0 : Module selection and arrangement and number of streams type 0 1 : Antenna group 1 0: Antenna selection 11: Precoding matrix coded thin feed 6 If the feedback type is '00', Refer to Table 5 contents. If the feedback type is '01', refer to Table 5. If the feedback type is '10', refer to Table 5. If the feedback type is '11', refer to Table 5 15 1374640 0 1 [Table 8] Description Ob 1 0 1 110 Antenna group A1 for ratio 1 · - BS for 3 antennas, see 8.4.8.3.4: BS for 4 antennas, see 8.4.8.3.5 Ob i 0 1111 for Antenna group A2 Ob 1 1 0000 for ratio 1 Antenna group A3 for ratio 1 • Ob 1 1 000 1 Antenna group B1 for ratio 2 BS for 3 antennas, see 8.4.8.3.4 for BS of 4 antennas, see 8.4.8.3.5 Ob 1100 1 0 Antenna group B2 for ratio 2 0b 1 1 00 1 1 Antenna group B3 for ratio 2 0b 1 1 0100 Antenna group for ratio 2 Group B4 (only for 4 antenna BS) 0b 1 1 010 1 Antenna group B5 for ratio 2 (only for 4 days • Line BS) Obi 101 10 for Antenna group B6 for ratio 2 (only for 4 days • Line BS) [Table 9] Value Description 16 1374640, ψ

Ob 1 0 1 110 Antenna selection item 〇Ob 1 0 1 11 1 Antenna selection item 1 Obi 1 0000 Antenna selection item 2 Obi 1 000 1 Antenna selection item 3 Ob 110010 Antenna selection item 4 Ob 1 1 001 1 Antenna selection item 5 Obi 10100 Antenna selection item 6 Obi 10101 Antenna selection item 7 Ob 110110 Reserved [Table 10] Value description 0b 1 0 1110 Reduce precoding matrix codebook entry 〇0b 1 0 1 111 Reduce precoding matrix codebook entry 1 0b 1 1 0000 Reduce precoding matrix codebook entry 2 0b 1 1 000 1 Reduce precoding matrix codebook entry 3 0b 1 1 0010 Reduce precoding matrix codebook entry 4 0b 1 1 0011 Reduce precoding matrix codebook entry 5 0b 1 1 0100 Reduce precoding matrix coding thin entry 6 Obi 10101 Reduce precoding matrix code thin entry 7 Obl 101 10 Reserved 17 1374640 * 1

In this particular embodiment of the invention, the contents of Table 5 and Tables 7-10 are known by both the BS and the MS and/or both the BS and the MS. According to this benchmark, the "feedback type" can be assigned to use the subheading of the table 7, while the "reward content" having one of the 6 and 6 bit lengths of the table 5 and the table 8-10 is only for describing the specific embodiment of the present invention. An example of feedback content. According to this arrangement, various types of feedback can be transmitted via a single header. Tables 5 and 8-10 are merely examples for describing the feedback content of a particular embodiment of the present invention. Preferably, the ΜΙΜΟ mode feedback sub-header can include a method for transmitting pre-encoded weight/antenna weight values in the closed-loop ΜΙΜΟ system, and can also be used in the ΜΙΜΟ mode and permutation scheme. Furthermore, it is preferred to include an indicator that indicates the method for transmitting the weight value in more detail (e.g., more explicitly) from a plurality of methods for transmitting pre-encoded weight/antenna weight values. .

Moreover, with respect to the direct precoding matrix value, it is preferable to quantize the directly determined weight value and use the 6 bits in each element of the matrix to transmit the quantized value. Modifications and variations of the various embodiments of the invention can be made without departing from the spirit and scope of the invention, as will be apparent to those skilled in the art. Therefore, it is intended that the present invention covers the modifications and variations of the invention, and are intended to fall within the scope of 18

Claims (1)

137.4640 (I iOt 7. 2© I year river beer replacement page | X. Patent scope: 1. A method of transmitting feedback information in a multiple input and output (ΜΙΜΟ) system' The method includes at least the following steps: Generating a step of 'generating a protocol data unit (PDU) comprising a &quot;media access channel (mac) header, an extended subheader group and a payload&apos; wherein the MAC header is included in either Extended subheader group Whether the group appears after the MAC header, wherein the extended sub-header group includes a mode feedback extension sub-header; and a transmitting step of transmitting the PDU, the PDU including the MAC header and the ΜΙΜΟ The mode feedback extends the sub-header, wherein the MIM mode feedback extension sub-header includes a request for a change in a transmit antenna type. Wherein the extension subheader 2. The method group as described in claim 1 is an extended subheader format (ESF). Such as the patent application scope H 1 annoyed #夕士, I The method of item 1, wherein the extended sub-header group occurs between the MAC header and the payload. 4. If the application for the patent Fangu type is in a closed loop 5. If the scope of the patent application is in the form of a closed interest road 6. If the patent application is based on the method described in paragraph 1 of the closed interest route, The antenna group information in the transmission antenna type system. The method of claim 1, wherein the transmitting antenna class selects group information in the system. The method of claim 1, wherein the pre-coding matrix in the transmission antenna class system is programmed 20 1374640 book. 7. The method of claim 1, wherein the transmission antenna type is channel matrix information in a closed loop system. 8. The method of claim 1, wherein if the ΜΙΜΟ mode feedback extension subheader is in a display state, the ΜΙΜΟ mode feedback extension subheader is transmitted by a mobile station (MS) Appears in a protocol data unit (PDU). 9. A method of transmitting feedback information in a multiple input/output (ΜΙΜΟ) system, the method comprising at least the steps of: receiving a feedback type intercept by a mobile station (MS); and transmitting a protocol data unit by the MS (PDU), the PDU includes a media access channel (MAC) header, an extended sub-header group, and a payload, wherein the MAC header includes an extended sub-header field (ESF), the ESF representation The extended subheader group is displayed in the PDU. The extended sub-header group immediately appears after the MAC header, and includes a module feedback extension sub-header, and wherein the ΜΙΜΟ mode feedback extension sub-header includes a feedback content field, the slewing The content interceptor includes at least antenna group information, antenna selection information, or reduced precoding matrix codebook according to the received feedback type field. 10. The method of claim 9, wherein the model 21 1374640 r~~ϊόττ:^··--------, the year of the year 3 is no more) is replacing the page i type feedback The extended subheader appears in a first protocol data unit (PDU) that is transmitted by the MS. 11. A mobile station transmitting feedback information in a multiple input/output (ΜΙΜΟ) system, the mobile station comprising: at least: a transmission module for transmitting a radio signal; and a receiving module, the The receiving module is configured to receive a radio signal, where the mobile station is set to: Receiving a feedback type field via the receiving module; transmitting, by the transmission module, a protocol data unit (PDU), the PDU including a media access channel (MAC) header, an extended sub-header group, and a payload, wherein the MAC header includes an extended sub-header (ESF), the ESF indicating that the extended sub-header group is displayed in the PDU, wherein the extended sub-header group is at the MAC Appears immediately after the header and includes an IΜ Ο module feedback extension subheader, and The ΜΙΜΟ mode feedback extension sub-header includes a feedback content field, and the feedback content block includes at least antenna group information, antenna selection information, or reduced pre-coding matrix coding according to the received feedback type field. thin. 12. The mobile station of claim 11, wherein the ΜΙΜΟ mode feedback extension subheader is present in a first protocol data unit (PDU) 22 1374640, the first protocol data unit being transmission. 13. A method for receiving feedback information in a multiple round-in output (ΜΙΜΟ) system, the method comprising at least the steps of: transmitting a feedback type field by a base station (BS); and receiving an agreement by the BS a information unit (PDU), the protocol information unit including a media access channel (MAC) header, an extended sub-header group, and a payload. Wherein the MAC header includes an extended sub-header field (ESF), the ESF indicating that the extended sub-header group is displayed in the PDU, wherein the extended sub-header group is immediately after the MAC header Appearing, and including a module feedback extension sub-header, and wherein the ΜΙΜΟ mode feedback extension sub-header includes a feedback content field, the feedback content 根据 position includes at least antenna group information according to the feedback type , antenna selection information, or reduced precoding matrix codebook. 14. The method of claim 13, wherein the ΜΙΜΟ mode feedback extension subheader is present in a first protocol data unit (PDU), the first protocol data unit being transmitted by the MS. 15. A base station (BS) for transmitting feedback information in a multiple input/output (ΜΙΜΟ) system, the base station comprising at least: a transmission module for transmitting a radio signal; and 23 1374640 years?· a receiving module, the receiving module is configured to receive a radio signal, wherein the mobile station is configured to: transmit via the transmitting module - receive through the receiving module - a feedback type field; and include a media storage a channel data receipt-representation data unit (PDU), the PDU (MAC) header, an extended sub-header group, and a payload, wherein the MAC header includes an extended sub-header (ESF), ESF indicates that the extended sub-header group is displayed in the PDU, wherein the extended sub-header group appears immediately after the MAC header, and includes a module feedback extension sub-header, and wherein the The ΜΙΜΟ mode feedback extension subheader includes a feedback content field. The feedback content field includes at least antenna group information, antenna selection information, or reduced precoding matrix codebook according to the feedback type field. 16. The base station of claim 15, wherein the ΜΙΜΟ mode feedback extension subheader is present in a first protocol data unit (PDU), the first protocol data unit being transmitted by the MS. twenty four